With the increasingly growing of the laser processing technology, a full monitoring of laser processing process (laser marking or laser cutting) is desired, so as to ensure the processing quality. Currently, the common monitoring method is to use CCD monitoring system to monitor the whole process. Compared with the conventional processing system in which focusing is performed with the naked eye at the beginning of processing, the CCD monitoring system can monitor the whole process. By monitoring the entire process, the parameters can be adjusted immediately in case of quality problems, thus ensuring the quality of processing.
The current CCD monitoring system has a “poor” vision at the wavelength in the far infrared light, and it has a higher sensitivity of the band in the red light region, thus the CCD monitoring system usually employ red light to work. However, when the system uses far-infrared wavelength laser to process, there is chromatic aberration in the imaging of the CCD monitoring system, which cannot faithfully reflect the processing in real-time.